My son is back again

As I type this, Nate is gleefully running up and down our narrow upstairs hallway bringing me Legos (they're not really Legos, but I don't know what the heck they are. They look like atoms that nest together). One by one by one - running up, running back. Lots of "bah! bah! bah!" and "pah!" as he goes. And now he's started throwing them, one by one, over the top of the banister and watching them fall down the stairs. He is such an incredible joy to have in my life. My heart is breaking open.